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It is well known that that corn (Zea mays) originated
in Mexico and that Mexican farmers have played a critical role in the
evolution of the plants genetic variability. As the plants
history unfolded, early corn races were transported to a wide variety
of ecological niches in which many distinct varieties developed. Mexico
became a centre of genetic diversity for corn, and its stock of germplasm
has contributed in a decisive manner to global production of corn. Even
the industrial varieties grown in the US Corn Belt are close descendants
of the first Mexican landraces.
Mexico is home to thousands of varieties of corn. The
germplasm bank maintained by CIMMYT (the International Center on Maize
and Wheat) in Mexico has 10,965 accessions, of which Mexican varieties
comprise one third. The Mexican government-owned gene bank managed by
INIFAP (the National Institute for Agricultural and Forestry Research)
has an additional 570 accessions. Mexican germplasm has played a critical
role in improving corn cultivated in tropical regions in relation to yield,
pest resistance, growth cycle, drought resistance and protein content.
It has also been instrumental in increasing yields in temperate varieties.
Mexican varieties and their derivatives have been used in 43 countries
in Latin America, Africa and Asia.
During the first half of the 21st century, it is expected
that most of the demand for corn will come from developing countries.
Little additional land is expected to come under cultivation in these
countries, thus production increments will have to come from greater yields.
Mexican corns genetic variability will have an important role to
play in improving production, together with germplasm developed in South
America and Africa.
In spite of the importance of Mexican corns genetic
variability, the North American Free Trade Agreement (NAFTA) looks set
to undermine and erode it. NAFTA presents a serious threat to Mexican
growers ability to conserve and develop these genetic resources.
Between 1992 and early 1993, Mexico negotiated NAFTA with the United States
and Canada. Probably the single most important element in NAFTA was the
inclusion of Mexicos most important crop corn. More than
one fifth of Mexicos active population of 39 million people work
in the agricultural sector. About three million of these are corn growers,
who generate about 18 tons of the countrys most important staple
in two agricultural cycles.
Opening up the market
Prying open the Mexican market had been an objective
of the powerful North American corn producers lobby since the 19th
century. With an annual production of 240 million tons, the US is the
largest producer of corn in the world, and carries a critical weight in
determining the international price of this basic commodity. From the
Mexican governments perspective, including corn in NAFTA would enable
the country to focus on more labour-intensive crops and to free up the
fiscal resources used to subsidise inefficient corn producers. There is
great heterogeneity in Mexicos corn sector and poor producers with
low yields coexist with those producing yields comparable to those found
in the US. Average national corn yields are less than 2 tons per hectare,
compared with 10-12 tons in the US. Mexicos policy makers felt that
the subsidies needed to support domestic growers were unjustified. By
purchasing corn from the US, where it is produced at roughly 40% of the
Mexican rate, the government promised that consumers would also benefit
from lower corn prices.
Another consideration was the objective of ensuring a
constant stream of cheap basic foodstuffs that would enable the Mexican
economy to maintain low wages, help to control inflation and increase
its capacity for capital accumulation. This is a shortsighted approach
since the impoverishment of farmers would inevitably become an obstacle
to growth, given the economys inability to provide gainful employment
for these rural producers when they are forced to migrate to urban areas.
Rhetoric concerning Mexicos comparative advantages and consumer
welfare was just a rationalisation for a short term capital accumulation
strategy. The decision to open Mexicos corn sector to US imports
handed this countrys massive tortilla market over to a group of
powerful industrialists. (Tortillas, or roasted corn pancakes, are the
most important corn product in Mexico). These business leaders were close
to Mexicos top decision makers at the time, and they continue to
benefit from government handouts to prevent tortilla prices rising.
It is important to note that in the NAFTA negotiations,
yellow corn and white corn, two distinct commodities in the international
market, were treated as one and the same commodity. Mexicos growers
engage essentially in the production of white corn, while US growers produce
yellow corn, most of which is used as livestock feed and about a quarter
of which is exported, mainly to China, Japan, Europe and, in growing quantities,
to Mexico. In spite of significant price differentials, with white corn
priced a full 25% above yellow corn in international markets, NAFTA treated
these two varieties as the same commodity.
A central pillar of NAFTA was the immediate replacement
of the corn tariff system with a a tariff-rate quota (TRQ) system. The
TRQ aimed to bring domestic prices in line with international prices by
gradually phasing out tariffs on all imports over a fifteen-year period
starting in 1994. All basic grains (including wheat, rice and sorghum)
were subjected to a rapid process of trade liberalisation and TRQ systems
were established for corn, barley and kidney bean (another important staple).
In the case of corn, an initial tariff-free quota of 2.5 million tons
was established, which would increase by 3% per annum.
The aim of this system was to protect domestic producers
during the transition period, but it has failed miserably. In practice,
all corn imports since 1994 have been tariff-free (more than 5 million
tons in both 1998 and 1999). Foregone fiscal revenues since NAFTAs
inception are estimated at more than $2,000 million dollars, a
figure comparable to fiscal appropriations for the entire agricultural
sector for the same period. According to official sources, the tariff
was not applied to excess imports for fear this would cause an increase
in tortilla prices. This in turn, it was argued, would accelerate inflation.
These arguments sound very hollow given that tortilla prices have increased
by a factor of 5 since NAFTA entered into force, while subsidies to the
flour industries (especially the two largest firms, MASECA and MINSA)
have almost doubled during the same period.
The Mexican governments failure to implement the
system of tariff rate quotas effectively eliminated all protection barriers
for corn producers. Corn prices were cut in half between 1994 and 2000
and domestic prices rapidly became aligned with international prices,
as can be seen in the graph below. Even the effect of the 1995 devaluation
was cancelled during this period and the livelihoods of millions of corn
growers and their families were laid on the line. In addition, PROCAMPO,
the income support mechanism established in 1994, lost half its value
in real terms and was insufficient to compensate producers for the price
reductions.

During this six-year period the agricultural sector experienced
a reduction of public support in other key areas such as credit, infrastructure,
research and development and technical assistance. The key public sector
agency used to regulate support prices for basic agricultural commodities
was dismantled in 1998, long before it could fulfil its role in the 15
year transition period. Thus, corn producers face the stark reality of
reduced prices in the context of a severe curtailment in credit, investment
in infrastructure and a reduction of the remaining support mechanisms.
According to the official studies justifying the inclusion
of corn in the NAFTA, proof of the inherent inefficiency of Mexicos
corn producers was found in the comparison between average production
yields in Mexico (2 t/ha) and the United States (12 t/ha). This difference
in productivity is explained by the very capital intensive agricultural
experience in the US, which relies on the use of heavy machinery, chemical
inputs and high-yielding varieties. The deep, well-drained soils of the
midwestern plains, together with a very regular rainfall pattern, offer
the ideal setting for the use of these inputs. This has led to a strong
specialisation in a limited number of breeds capable of high yields, with
five or six lines dominating the corn-producing landscape. While yields
may be impressive, this agricultural model comes with significant costs
to the environment, sustainability and genetic diversity. The vulnerability
of such specialisation was demonstrated in 1970 when the Southern corn
leaf blight epidemic wiped out 25% of the US corn crop.
In sharp contrast, the vast majority of Mexicos
corn growers rely heavily on a wide variety of landraces as their main
guarantee against crop failure. Producers of corn in more marginal areas,
such as uplands or tropical and subtropical environments, encounter many
sources of risk and uncertainty, and the most important technological
asset at their disposal is the genetic variability of their corn.
Corns careful curators
Every year, approximately two million corn growers in
Mexico engage their attention and collective experience in the art of
selecting seeds for the next agricultural cycle. The seeds are selected
according to their ability to respond to the environmental and physical
characteristics of the regions in which the farmers operate. Most
of these planters grow their corn in mountainous areas and their plots
are subjected to an irregular rainfed regime. Their plots are located
in sloping terrain or in the valleys, and these upland production conditions
frequently include poor soils, strong winds, early frost, and diverse
pests. In the lowlands, close to the coastal plains or in some inland
depressions, the tropical environment entails difficult production and
post-harvest conservation conditions due to pests and poor soils.
The seeds selected by these growers are rich in gene-based
mechanisms enabling them to resist pests of all kinds, from weevils to
worms and fungi, or to grow even when the first rains are interrupted
and plants are at their most vulnerable stage of growth. Some seeds bear
plants which are well adapted to poor soils, others produce early-maturing
varieties, which are particularly important in upland areas susceptible
to early frosts. Others have a hard pericarp (protective coating surrounding
the seed) which keep the seeds viable for long periods, important under
tropical conditions.
The intense genetic-environment interaction displayed
by corn enables the plant to adapt to highly contrasting environments.
Mean growing season temperatures can exceed 26º C or may be as low as
12.5º C, and corn can be cultivated from sea level to 4,000 metres above
sea level. It can be grown on fully irrigated or semi-arid land, with
growing cycles varying between 3 to 12 months. Height can vary from 65
centimeters to four metres. Finally, corn can be adapted to various soil
types. This great capacity to adapt to widely differing environments found
in Mexicos rich tapestry of varied ecological niches, makes corn
the perfect ally to minimise risks.
In Mexicos mountainous areas, growers normally
sow at least two corn varieties, one which is less productive but matures
early and is capable of beating the onslaught of early frosts, and one
which is more productive but slower to mature. In many communities, up
to eight varieties are employed. The most important factors determining
seed selection are the type of soil, drought and wind resistance, response
to inputs, vulnerability to weeds, optimum period of fertility, yield,
end uses (sale, domestic or ritual), post-harvest conservation and dietary
considerations (flavour, grain texture and colour). Normally none of the
selected cultivars shows high performance scores in more than one or two
of these variables. It is because of this negative correlation, the quest
for particular qualities in the corn they grow and the heterogeneity of
their growing environments that farmers continue to maintain and enhance
the gene pool.
But Mexican farmers critical role as curators of
the global corn gene pool went unrecognised in the NAFTA negotiations.
The fact that the best US hybrid seeds would be outperformed by Mexicos
landraces in most of the environments in which corn is produced in this
country was also ignored by government spokespersons. Under conditions
of poor soil fertility, hybrids frequently yield less than local landraces.
In addition, Mexican highland germplasm displays an exceptional ability
to withstand frost and hail, and to emerge from deep planting (an important
quality when the initial rains are interrupted) with good quality grain.
This capacity of local landraces to outperform modern high-yield hybrids
under conditions of biotic and abiotic stress is based on the plants
excellent adaptive features and this explains why penetration of hybrids
in corn production has never reached the high rates obtained in wheat
production. In Mexico today the use of hybrid varieties is restricted
to about 25% of the corn area.
Another key aspect of corn production in Mexico is that
growers relying on local landraces are usually the poorest producers,
endowed with very small plots of land (averaging less than 2 hectares),
little or no access to credit, limited or minimum use of chemical inputs
and usually no mechanical traction. The regions where these producers
operate exhibit the highest incidence of rural poverty. As the map below
shows, these producers are found in the Central and Southern highlands,
in tropical and semi-tropical areas, or in semi-arid regions. Their economic
vulnerability is countered mainly through the use, conservation and development
of corns genetic resources. The harsher the environment, the more
innovative the farmers need to be and the more risk-reducing strategies
are needed. For this reason, the poorest producers are the most important
curators of corns genetic resources. But the logic embedded in NAFTA
is for these poor producers to depart from the corn sector (if not agriculture
altogether) in order to enable the economy attain a higher level of efficiency.


Conserving corns cultural roots
Corns genetic diversity is also related to the
presence of different indigenous groups for which corn cultivation is
not only a means to ensure physical subsistence, but also part of a deeper
social and cultural process. Approximately 60% of corn growers are indigenous
peoples. The strong interaction between culture and corns genetic
variability is illustrated by the fact that many local languages identify
more stages of plant development and a richer plant anatomy than conventional
botanical literature. Because of the close interaction between social
and cultural systems and genetic diversity, the displacement of people
and the destruction of social institutions are causes of genetic erosion.
For example, collective action by communities where social, family and
ritual bonds are strong is frequently required to plant or harvest. But
this collective action becomes more difficult as the social base sustaining
it is gradually eroded.
The capacity to conserve, select and develop genetic
resources depends on factors at the household, social and institutional
levels. At the household level, individual growers transmit from one generation
to another the information required to select seeds for their use in different
agroenvironments. Farmers also engage in exchanges with other farmers
and communities. Experimentation with other varieties and breeding of
new varieties is part of a dynamic process in which landraces are used,
preserved and refined in multiple cycles through the flow of genetic material.
This educational process requires both adequate living standards as well
as the support of a strong institutional base. The social fabric that
sustains this process is already being damaged through economic pressure,
and the capacity to conserve and develop genetic resources may be irrevocably
lost. Many corn growers are being forced to migrate. Recent research has
revealed that the propensity to migrate is stronger in areas where poor
corn growers using local landraces operate. As mid-sized producers are
forced out of the corn market, poorer farmers who relied on these farms
for employment are driven to labor markets further away. Other sources
of income, such as basket weaving or knitting, are also affected by the
drop in rural wages because of reduced demand.
In spite of the drop in corn prices and the increase
in imports, Mexicos production has remained stable so far.
But this should not obscure the fact that economic stress on the poorest
producers will soon reach a threshold beyond which they cannot survive.
The apparent stability in corn production is the consequence
of how poor producers respond under stress, relying more on the resources
at their command (land), and is not a sign of economic health. Proof of
this is the fact that the cultivated surface devoted to corn has increased,
while yields have dropped. This demonstrates that there is greater pressure
on existing resources.
The situation of subsistence farmers requires special
attention. All pre-NAFTA studies justifying the inclusion of corn in the
trade pact assumed that subsistence growers would not be affected by the
price reductions. It was assumed that because the crops of these producers
are not marketed, price cuts would leave them unaffected and, in fact,
the reduction of tortilla prices would be beneficial. However, this view
ignores the fact that subsistence producers do not live in economic isolation
and that many of their needs have to be satisfied through purchases of
marketed commodities, which requires cash. Household income is obtained
from various sources: local off-farm labour, remittances from migrant
workers, and petty sales of grain. These petty sales take place in a buyers
market and are therefore marked by low prices. The grain sold in this
way must be replaced later, in a sellers market which imposes higher
prices. If the grain deficit is not replaced, the household will have
to buy tortilla dough later, exacting even higher costs.
The capacity to carry out the process of conservation
and development of corn genetic resources depends on the knowledge base
of households and communities. As migration takes place, and as the pressure
of poverty is endured, the capacity to conserve and develop these resources
is severely diminished. Poverty and migration conspire together to leave
behind a deteriorated capacity to select seeds according to relevant criteria,
and to identify the specific agro-environments into which each class of
seeds can be productively inserted. The process of genetic erosion mediated
through the disappearance of the institutional and social base is one
of the major threats to Mexicos corn growers and their capacity
to improve their livelihoods.
The first step in this process of genetic erosion is
more related to the loss of information on genetic variability than to
the loss of specific genotypes. Genotypes may be preserved for some time
in gene banks. But because genetic variability is mediated by social groups
or institutions, the reduction in genetic variability will take place
when the social group acting as curator of this resource disappears. The
position of the corn producers in Mexico that perform this important service
is increasingly perilous thanks to the economic forces unleashed by trade
liberalisation. NAFTA is pushing to eradicate corns curators from
the agricultural landscape, a move which will have a profound impact on
global food security in the twenty-first century.
Alejandro Nadal is coordinator of the Science and Technology
Program at El Colegio de México. This article is largely based on research
undertaken for the World Wild Fund for Nature (WWF International) and
OXFAM (UK) on the environmental and social impact of the inclusion of
corn in NAFTA. The final report, "Zea Mays: The Social and Environmental
Effects of Trade Liberalisation in Mexicos Corn Sector" is
to be published in September 2000. The views expressed in this article
are the authors alone. He can be contacted at anadal@prodicgy.net.mx
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